U.S. patent application number 11/897065 was filed with the patent office on 2008-03-06 for adapter for air purifying filter.
Invention is credited to Christopher G. Estkowski, John A. Ratajczak.
Application Number | 20080053447 11/897065 |
Document ID | / |
Family ID | 39027203 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080053447 |
Kind Code |
A1 |
Ratajczak; John A. ; et
al. |
March 6, 2008 |
Adapter for air purifying filter
Abstract
An adapter for use with a gas filter canister worn by a user as
part of a breathing apparatus. The adapter is constructed of a
semi-rigid plastic that has a plurality of scalloped or castellated
edges. The scalloped or castellated edges allow the adapter to
snap-fit over the top of the canister. Projections or lugs on the
inside of the edge of the adapter can deflect and snap over the rim
of the canister. An adapter seal in the form of a large preformed
packing or O-ring, is pressed between the inside of the adapter top
and the outside of the canister top such that an airtight seal is
formed. The adapter is capable of moving relative to the filter
canister to accommodate different positions of the flexible conduit
between an adapter inlet and the outlet of a self contained blower
assembly.
Inventors: |
Ratajczak; John A.;
(Lancaster, NY) ; Estkowski; Christopher G.;
(Pullman, MI) |
Correspondence
Address: |
HODGSON RUSS LLP;THE GUARANTY BUILDING
140 PEARL STREET, SUITE 100
BUFFALO
NY
14202-4040
US
|
Family ID: |
39027203 |
Appl. No.: |
11/897065 |
Filed: |
August 29, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60841182 |
Aug 29, 2006 |
|
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|
Current U.S.
Class: |
128/205.25 |
Current CPC
Class: |
A62B 7/10 20130101; A62B
9/00 20130101 |
Class at
Publication: |
128/205.25 |
International
Class: |
A62B 18/02 20060101
A62B018/02 |
Claims
1. An adapter for use with a filter canister, the filter canister
having a rim on the inlet end, the adapter comprising: a top wall;
a side wall connected to the top wall; at least one lug extending
from the side wall, the lug sized to frictionally fit over the rim
of the filter canister when the adapter is joined with the filter
canister; at least one seal disposed between the adapter and the
filter canister when they are joined together; an adapter inlet
extending from the top wall; and wherein the adapter is capable of
moving relative to the filter canister when the adapter is joined
with the filter canister.
2. The adapter of claim 1, wherein the side wall has at least one
opening defined therein.
3. The adapter of claim 2, wherein the at least one opening
comprises a plurality of U-shaped openings forming a scalloped
bottom edge of the side wall.
4. The adapter of claim 1, wherein the at least one lug comprises a
plurality of lugs.
5. The adapter of claim 1, wherein the at least one lug extends
substantially perpendicular to the side wall.
6. The adapter of claim 1, wherein the at least one seal is an
O-ring.
7. The adapter of claim 1, wherein the O-ring is larger than a
space between the top wall of the adapter and the filter canister,
the space being created when the adapter is joined to the filter
canister, the size differential between the space and the O-ring
causing the O-ring to be compressed when the adapter is joined with
the filter canister.
8. The adapter of claim 1, wherein the adapter inlet is disposed at
an angle relative to the canister.
9. The adapter of claim 1, wherein the adapter is round.
10. The adapter of claim 9, wherein the adapter is capable of
rotating relative to the filter canister.
11. A breathing apparatus for mounting on the body of a user, the
breathing apparatus, comprising: a filter canister having a rim on
the inlet end and having an outlet; an adapter having a top wall, a
side wall connected to the top wall, the side wall having at least
one lug sized to frictionally fit over the rim of the filter
canister, the adapter having at least one seal disposed between the
adapter and the filter canister when the adapter is joined to the
filter canister, the adapter having an inlet; a self-contained
blower assembly disposed in fluid communication with the adapter
inlet; a breathing mask in fluid communication with the outlet of
the filter canister; wherein the adapter is capable of moving
relative to the filter canister when the adapter is joined with the
adapter.
12. The apparatus of claim 11, wherein the side wall has at least
one opening defined therein.
13. The apparatus of claim 12, wherein the at least one opening
comprises a plurality of U-shaped openings extending to a bottom
edge of the side wall.
14. The apparatus of claim 11, wherein the at least one lug
comprises a plurality of lugs.
15. The apparatus of claim 11, wherein the at least one lug extends
substantially perpendicular to the side wall.
16. The apparatus of claim 11, wherein the at least one seal is an
O-ring.
17. The apparatus of claim 11, wherein the O-ring is larger than a
space between the top wall of the adapter and the filter canister
such that the O-ring is compressed when the adapter is joined with
the filter canister.
18. The apparatus of claim 11, wherein the adapter inlet is
disposed at an angle relative to the canister.
19. The apparatus of claim 11, wherein the filter canister is a
C2A1 model.
20. The apparatus of claim 11, wherein the blower assembly is
mounted to the shoulder of the user.
21. The apparatus of claim 11, wherein the filter canister and
adapter are joined together and supported on the arm of the
user.
22. The apparatus of claim 11, further comprising a first flexible
conduit disposed between the self-contained blower assembly and the
inlet to the adapter.
23. The apparatus of claim 11, further comprising a second flexible
conduit disposed between the outlet of the filter canister and the
breathing mask.
24. The apparatus of claim 22, wherein the movement of the adapter
relative to the filter canister accommodates different positions of
the first flexible conduit resulting from movement of the user.
25. A breathing apparatus for mounting on the body of a user, the
breathing apparatus, comprising: a filter canister having an inlet,
a rim on the inlet end, and having an outlet; an adapter having a
top wall, a side wall connected to the top wall, the side wall
having at least one lug extending therefrom, the lug sized to
frictionally fit over the rim of the filter canister to join the
adapter to the canister, the adapter having at least one seal
disposed between the adapter and the canister when the adapter is
joined to the canister, the adapter having an inlet, the adapter
being capable of moving relative to the filter canister when the
adapter is joined to the canister; a self-contained blower assembly
disposed in fluid communication with the adapter inlet; a first
flexible breathing conduit disposed between the blower assembly and
the adapter inlet; a breathing mask in fluid communication with the
outlet of the filter canister such that filter air is conveyed to
the user; wherein the movement of the adapter relative to the
filter canister accommodates different positions of the first
flexible conduit resulting from movement of the user.
26. The apparatus of claim 25, wherein the adapter inlet is
elongate with a first end and a second end centered over the filter
canister inlet.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/841,182 filed on Aug. 29, 2006, which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a breathing
apparatus for contaminated areas and specifically to an adapter for
use with an air purifying filter.
BACKGROUND OF THE INVENTION
[0003] For the protection of air crew members against breathing
contaminated air in aircraft that do not supply oxygen to the air
crew or when the air crew is not utilizing the oxygen supply, the
crew members typically have a blower assembly, which takes in
ambient air, strapped to their body. The blower assembly forces the
air through a canister which purifies the air and delivers the air
through a system of hoses to a facepiece worn by the crew member.
In the event that the crew member exits the aircraft in a
contaminated area, they would exit with the blower assembly
connected to the canister and the canister connected to their
facepiece.
[0004] Typically, this type of arrangement in the past required
placing the canister inside a bulky housing or encapsulating it in
an elastomeric boot which may restrict flow through the system.
Also, when climbing out of the aircraft and walking away from the
aircraft, the objects strapped to the body tend to shift resulting
in pulling and tugging of the parts. This pulling and tugging can
lead to partial crimping of the hoses and a resulting reduction in
airflow through the canister.
[0005] What is needed is a device that closely follows the profile
of the user such that the hose from the blower to the inlet of the
canister can approach the canister at right angles instead of
axially, such that relative motion between the blower and the
canister can be accommodated by swivelling action of an adapter on
the canister, and such that the device does not restrict flow.
SUMMARY OF THE INVENTION
[0006] The present invention meets the above-described need by
providing an adapter for use with a gas filter canister. The
adapter is constructed of a semi-rigid plastic that has a plurality
of scalloped or castellated edges. The scalloped or castellated
edges allow the adapter to snap-fit over the top of the canister.
Projections or lugs on the inside of the edge of the adapter can
deflect and snap over the rim of the canister. An adapter seal in
the form of a large preformed packing or O-ring, is pressed between
the inside of the adapter top and the outside of the canister top
such that an airtight seal is formed. Also, the seal provides
sufficient friction to allow the adapter to swivel on the top of
the canister.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention is illustrated in the drawings in which like
reference characters designate the same or similar parts throughout
the figures of which:
[0008] FIG. 1 is a perspective view of the adapter of the present
invention attached to a filter canister;
[0009] FIG. 2 is a top plan view of the adapter;
[0010] FIG. 3 is a side elevational view of the adapter of the
present invention attached to a filter canister;
[0011] FIG. 4 is a cross-sectional view taken along lines 4-4 of
FIG. 3;
[0012] FIG. 5 is an enlarged detail view of a portion of FIG. 4;
and,
[0013] FIG. 6 is a perspective view showing an adapter of the
present invention installed on a canister strapped to the body of
an aircraft crew member.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIGS. 1-6 and initially to FIG. 1, an adapter
10 is attached to a filter canister 13. The adapter 10 can be sized
to fit any standard gas mask canister with a bead or rim on the
inlet end and that does not have a fitting at the inlet. If the
canister is circular the adapter 10 will swivel as described below.
The canister 13 may be a standard military C2A1 model with an
opening 16 (shown in FIG. 4) at the top that receives ambient air
and has no fitting. An outlet 19 (FIGS. 3-4) is positioned at the
bottom of the canister 13. The outlet 19 may be equipped with a
screw threaded fitting 100 (FIG. 6) that may be equipped with a
ninety degree elbow as will be described below.
[0015] The adapter 10 may be provided with a plurality of channels
11 around the periphery of the device forming a plurality of
scalloped or castellated edges. The adapter 10 includes an inlet
22, a top wall 25, and a side wall 28. The side wall 28 extends for
a relatively short distance in a direction substantially
perpendicular to the top wall 25. The side wall 28 has channels 11.
The shape and the number of the channels 11 combine with the
properties of the materials of construction for the adapter 10 to
provide flexibility for fitting the adapter 10 over the canister 13
as will be described in detail below. The adapter 10 may be
constructed from DuPont Zytel 80G14A NC010A. This material is a 14%
glass filled, toughened, high flow polyamide 66 resin. The glass
fiber reinforcement provides increased modulus to allow a snug snap
fit of the adapter 10 onto the canister 13 and strength to resist
breakage during assembly. The toughening provides good impact
properties, and the high flow property of the material improves
mold fill thereby reducing the appearance of knit line weakness in
the adapter during molding. Other plastic and composite materials
that are semi-rigid may also be suitable.
[0016] The inlet 22 is disposed at an angle .beta. with respect to
a horizontal axis 29 as best shown in FIG. 3. The angle .beta. is
determined by a number of factors including providing a low profile
for the unit that does not interfere with the seal over the bead or
rim 40 on the canister 13 and providing flow at or near the center
of the canister 13. The canister 13 has a side wall 90, a bottom
wall 93, and a lid 96 (FIG. 4).
[0017] Turning to FIG. 4, the canister 13 has an inlet 16 that is
disposed along a central longitudinal axis 34 of the canister 13.
The outlet 19 of the canister 13 is also disposed along the
longitudinal axis 34. The outlet 19 may be provided with a screw
threaded fitting as described below. The adapter 10 has a plurality
of lugs 37 (FIG. 5) that snap fit over the rim 40 of the canister
13. As best shown in FIG. 5, the lugs 37 are disposed substantially
perpendicular to the side wall 28.
[0018] As shown in FIG. 5, the canister 13 has a lid 96 that
extends to the rim 40. The rim 40 is disposed around the periphery
of the canister 13 and forms a shoulder 48 that extends to the side
wall 90 of the canister 13.
[0019] As best shown in FIGS. 4-5, the adapter 10 creates a plenum
chamber 44 between the top wall 43 of the filter canister assembly
and the inside surface of the adapter 10.
[0020] An O-ring type seal 55 may be disposed around the periphery
of the canister 13 as best shown in FIG. 5. The O-ring seal 55 is
oversized such that when the adapter 10 is snap fit onto the
canister 13 the seal is compressed between the lid 96 of the
canister 13, the top wall 25 of the adapter 10 and the rim 40 on
the end of the canister 13, to form a substantially airtight seal.
The gas seal 55 may be constructed from EPDM foam rubber material.
The durometer may be approximately 50 Shore A with a tensile of
1500 psi and a stretch limit of 200%. EPDM is highly resistant to
the types of chemical agents that the C21A filter protects against.
The O-ring type seal 55 is designed oversize to bias the seal 55 to
the inside of the rim 40 of the canister 13 and maintain force away
from the center of the filter canister 13 to ensure the seal 55
stays in position. The seal 55 may be provided with a 3/8 of an
inch diameter. A larger diameter seal can take the increased radial
seal compression before buckling. As the seal 55 is compressed it
has to be sufficiently large in diameter and of the proper material
to resist the force being applied by the filter inside rim 40 and
the adapter 10 to maintain proper position and compression. As a
result of the oversize seal condition, the seal 55 can be
pre-installed in the adapter 10, providing the user the ability to
install the adapter 10 directly on the filter 13 without taking the
time to pre-align the filter canister 13/adapter seal 55.
[0021] The plenum chamber 44 created between the filter canister
assembly lid 96 and the inside surface of the adapter 10 reduces
the effects of flow directional change on resistance. To further
reduce resistance from turbulent flow the adapter inlet opening 99
(FIG. 4) is centered over the canister inlet 16 so airflow is
directed into the filter inlet orifice 16.
[0022] The adapter seal 55 may be adjusted to provide for
resistance that allows the adapter 10 to swivel on the top of the
canister 13. The adapter 10 rotational resistance is controlled by
the material type of the adapter seal 55 and the amount of
preloaded force applied to the seal 55 resulting from the geometry
of the adapter inner seal surface 56 in relation to the lug
engagement face or shoulder 48. Adjusting this distance can vary
the resistance required to rotate the adapter 10 to the desired
position and varies based on the seal material type. This
characteristic allows the adapter 10 to be rotated into a desired
position by hand yet maintain this position during use. The adapter
10 installation force is controlled by the plurality and the
geometry of the lugs 37 used to engage the filter rim 40. There may
be ten or more lugs 37 but as few as two lugs 37 can be used to
break the hoop strength of the adapter rim cylindrical engagement
wall and allow the wall to flex outward while the lug 37 negotiates
around the rim 40 of the filter canister 13. Once past the filter
rim 40 the lug 37 maintains sufficient force against the filter
body wall 90 to ensure the adapter 10 is secured to the filter
canister 13 by using the remaining hoop strength characteristic in
a curved surface bending perpendicular to the radius and the
engineering properties of the material used in the construction of
the adapter 10. These properties provide the modulus, tensile and
flexural strength required by the application.
[0023] Turning to FIG. 6, the adapter 10 of the present invention
is shown in use with a canister 13 and a blower assembly 70 that
are strapped to the body of an aircraft crew member. As shown, the
blower assembly 70 is mounted to the shoulder of the aircraft crew
member. A hose 73 extends from the outlet 76 of the blower assembly
70 toward the inlet to the adapter 10. The hose 73 from the blower
assembly 70 attaches to the inlet 22 of the adapter 10 at a
position that is approximately 90 degrees to the inlet 16 of the
filter canister 13. The adapter 10 and the adapter inlet 22 are
capable of rotating relative to the filter canister 13 so that
movements of the body of the crew member can be accommodated
without crimping the hoses.
[0024] At the outlet of the canister 13 a fitting 100 may be
provided with a ninety degree elbow 80 that connects to a hose 83.
The hose 83 runs to the facepiece 86 to provide breathable air to
the user. Accordingly, the blower assembly 70 takes in ambient air
which is then forced through the canister 13 and conveyed to the
facepiece 86 of the user to provide breathable air in contaminated
areas.
[0025] While the invention has been described in connection with
certain embodiments, it is not intended to limit the scope of the
invention to the particular forms set forth, but, on the contrary,
it is intended to cover such alternatives, modifications, and
equivalents as may be included within the spirit and scope of the
invention as defined by the appended claims.
* * * * *